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BENJAMIN r. AIKEN, JR, or MILLBURY, ASSIGNOB or onnrmrr 'ro CHARLES W. NEWHALL, 3a., or won'ons'rnn, MASS.

WIRE OR METAL CLEANlNG BATH.

SPECIFICATION forming part of Letters Patent No. 288,150, dated November 6, 1883. Application filed April 3, 1883. (No specimens.)

T aZZ whom it may concern:

Be it known that I, BENJAMIN F. AIKEN, Jr., a citizen of the United States, residing at Millbury, in the county of lVorcester and State 5 of Massachusetts, have invented a new and useful Improvementin Wire and Metal Cleaning Baths, of which the following is a specification, containing such a full, clear, and exact description as will enable any one skilled in the art to use the same.

My improved cleaning-bath maybe used for cleaning metallic surfaces of oxides or foreign substan ces; but it is especially adapted to and valuable for cleaning wire or wire rods, either preparatory to their being drawn or preparatory to their being coated with zinc, tin, cop- 'per, or other metal, or for other purposes.

In the successive processes of drawing wire the iron becomes fibrous and requires to be annealed to render it ductile, and in the operation of annealing its surface becomes more or less covered with an oxide scale, which must be removed before the operation of drawing can be continued. This is commonly done by immersing the wire in a hot bath of diluted sulphuric acid for a shorttime, and then checking the action of the acid upon the metal, or

devitriolizing it, by immersing the wire in a bath of hot water or subjecting it to a current of cold water; otherwise the excessive action of the acid bath would render the wire brittleand unfit to be drawn. The wire or wire rods are then coated or covered with a paste of meal or flour, clay, or a solution of salt or of lime, or of salt and lime, either alone or in connection with oil or fatty substances, which act as lubricants to the surface of the wire as it passes through the die-plates.

I use, instead of the bath of dilute sulphuric acid above mentioned, a bath formed by addin g to water acleaning corrosive acid. In case the wire is to be drawn I use sulphuric acid. In other eases-such as when coating with zinc or tin-hydrochloric or nitromuriatic acid may 'be used, and to the acid and water I add cyanogen, generally and for convenience in the form of a metallic cyanide. In practice I prefer the cyanide of potassium, and to each gallon of water I use from one to eight ounces of 50 sulphuric acid, and from one-eighth ofan ounce to one ounce of the cyanide of potassium. The condition and size of the wire and othervarying circumstances render it impossible to state 7 the exact strength of the bath required or the exact proportion of the several ingredients 5 5 suitable under all the varying conditions of use; but these can be readily ascertained and determined by any one skilled in the art as the occasion demands.

By the combination, with an acid cleaningbath, of cyanogen in the form of a soluble metallic cyanide I increase the efficiency of the acid bath and effect a great saving in the cost of cleaning. I also obviate to a considerableextent the injurious results of the eX- cessive action of the sulphuric-acid bath in rendering the iron brittle, arising either from the absorption of free hydrogen or from other causes. A coating of ferro cyanide is also formed upon the surface of the wire, which in some cases may enable it to be drawn one or more times without the use of the flour, clay, salt, or lime coating commonly employed, and in case such a coating is used the. ferro-cyanide coating formed in the bath will aid in the lubrication of the wire.

The employment of a ferro-cyanide coating or covering as a lubricant in the process of wire-drawing, although considered new and useful, I do not herein claim, deemingv it advisable to make such a use the subject of a separate application.

I apply heat to the cleaning-bath by either heating it in a kettle orby introducinga steamjet, or by any known and convenient method. If, however, a steam-jet is used, the bath will undergo a constant dilution, owing to the condensation of the steam, which may be easily provided for, as is now done in the ease of the sulphuric-acid bath. After the immersion of the wire a sufficient length of time, which will vary according to the condition and size of the wire, I check the action of the bath by subjecting the wire to a currentof cold water, or by the use of any of the known means for the purpose. In some cases the bath may preferably be used cold.

For greater convenience in using the cleaning-bath herein described, I prefer, instead of employing the several ingredients separately, 10o

2 assnrso to use a solution of the acid and the cyanide, Which Will then only require the proper dilution with Water to render it adaptable for use.

I am aware that a solution of the cyanide of potassium has been long in use as a menstruum or solvent solution for various metals in the process of electro-deposition. Such an application I do not claim; but

hat I do claim as my invention, and desire to secure by Letters Patent, is

1. The improved wire or metal cleaning bath herein described, consisting of a mixture, with a sulphuric-acidbath, of the cyanide of potassium, as described, and for the purpose set forth.

2. The improved Wire or metal cleaningwith a sulphuric-acid bath, of a soluble metallic cyanide, as described, and for the purpose set forth. Y

3. The improved wire or metal cleaning bath herein described, consisting of a mixture, with a suitable acid cleaning-bath, of a soluble metallic cyanide, as described, and for the purpose set forth.

. BENJ. 1: AIKEN, JR; Vitnesses:

R. B. FOWLER, MIRIcK H. Oo nIN. 

